Fastener



vJuly l0, 1945. A. vENDlTTY 2,380,131

` FASTENER Filed June 4, 1942 All C E Mea/72 Patented July 10, 1945 Anthony Venditty,l Detroit, I Mich., assignor to Thompson Products, inc., a. corporation of- Ohio Application June" 4, 1942, Serial No. 4455-746 11o claims. y(o1. .ai-"2am This invention relates to fastening devices for detachably connecting parts, such ask apertured plates;

Specioally the invention relates to separable fasteners useful in detachably connecting airplane coWling,A airplane inspectionv plates',4 automotive accessories, and the like.

The fasteners of this invention are composed of' areceptacle anda stud. The stud andI receptacle have cooperating locking instrumentalities.

The receptacle may be in the. formof a spring platewith a stud-receiving apertureV therein and with feet portions supporting the apertureed'ening portion on an innermost apertur'ed part in spaced relation from theaperture of the part. The'` stud member is adapted to be rotatably mountedin the aperture of an outermost part and has` a shank portion extending. through the apertures of both parts into the aperture of the tation. To this end', the stud shank is helically grooved so as to provide double tapered threads starting from a common point at the free end of the' shank and diverging along helical paths outwardly toward the periphery of the shank portion to undercut slots. The spring plate aperture is" Wide enough to cooperate with the tapered threads' Without being subjected to a spreading action. In other Words;Y the stud can be threaded ntotheaperture of the spring plate and held in this aperture by cooperation between the undercut; grooves and the aperture-defining Walls. When the studI is' rotated to seat the aperturedening walls in the undercut grooves, portions of the stu'd Will overlap the spring plate onboth sides of the plate. t

The spring fingers are effective in holding the stud" against unauthorized" rotation so' as toV maintain theL parts in fastened relation even though springplate. The portion of the shank which eX- tends into the, aperture of the spring plate has thread-like cam surfaces thereon adapted to engage the aperture-defining; portion of the spring plate to deeot the samey toward the innermost part on which the springlplate is mounted. This will draw the two parts together. y.

The spring plate has springiingers thereonwith free ends adapted to engage flat spots or abutment: surfaces on the stud soV as to prevent unauthorized" rotationof the stud.

As. the spring plateis deflected by threading of the stud therein, the free ends of the spring ngersare automatically moved into position so that theyfwill tightly seat against the abutment surfaces provided onthe stud when thelstud.l has beenrotated' to locked position. In other Words, as. the aperture-deriningl portion of the spring plate, isv drawn toward the part on which the plate is. mounted the. lingers likewise are deflected'` to position their free ends closer together so that they will have better gripping` engagement with the flat. spots on the stud.` This feature, how'- ever, is. not essentialt'o the* operationof the fas'- tenerssince. the lingers overlie the aperture ofthe spring plate and havey their` free` ends deflected away `from eachother as the stud is threaded-- into the, aperture. Such lateral. deflection ofthe free ends. of the, spring lingers will, of coursegplace the. iingersunder load so that they will have` good gripping action.y against. the at spots or abutment. shoulders on which they are seated when the.` studlis rotated= to completely' locked position.

The jthread' or camsurface on thestudV is are the assembly is subjected toK extreme vibration and' toL other forces tending to unfasten the parts. However, the spring fingers can be deected outwardly so as to release their grip on' the stud Whenever the'stud is manually rotated to unf asten the parts.

It is,` then', an object of this invention to providefasteners forv detachably connecting a plurality of parts and for" holding said parts in connected relation even though the assembly is subjected to extreme vibration tendingto disconnect the parts.

A stilll further object of this invention is to provide a' fastener Which locks and unlocks upon reverselquartereturn rotation of a' stud and which is equipped; with spring fingers preventing unauthorized unlocking of the parts.

A still iurther'obje'ct ofthe invention is to provide a' separable fastener especially adapted for use in securingairplan'e' cowling in position on an A speeine'obiect of the invention is te provide a fastener composed of a spring plate for attachment toan innermostpart having a stud-receiving aperture and. spring arms with free end portions overlying; said aperture to! cooperate with a stud inserted through the apertureror' holding' the' stud against unauthorized" rotation.

mounted in the grommet G carried by the outer plate A.

The receptacle I I is conveniently stamped from a flat piece of metal and has a pair of feet IIa, IIa on opposite sides of the dimple B'. The feet IIa, Ila are apertured to receive therethrough the shanks of rivets I3 which secure the receptacle to the plate B. As shown in Figures 4 pair of plates held together by a fastener ac- I' cording to this invention and illustrating thel head of the fastener stud seated in an embossed dimple of the outer plate.

Figure 2 is a bottom plan or inside plan view of the pair of plates shown in Figure 1 and illustrating the receptacle of the fastener mounted on the inner plate and cooperating with the stud of the fastener to hold the plates together.

Figure 3 is a side elevational View of the assembly shown in Figures 1 and 2.

Figure 4 is a side elevational View, with parts shown in vertical cross section, illustrating the assembly of Figures 1 to 3 just before the stud is rotated to completely locked position, for showing the manner `in which the spring arms of the receptacle ride on the cam surfaces of the stud as the receptacle is being deflected by the stud threads.

Figure 5 is a cross-sectional View, with parts in elevation, taken along the line V-V of Figure 4.

Figure 6 is a vertical cross-sectional view, with parts in elevation, taken along the line VI--V'I of Figure 2.

Figure '7 is a horizontal cross-sectional view, with parts in elevation, taken along the line VII-'VII of Figure 3.

Figure 8 is a plan view of the stud shown in Figures 1 to '7 looking down from the apex of the stud shank.

Figure 9 is a side elevational view of the stud shown in Figure 8.

Figure 10 is an enlarged fragmentary side elevational view, similar to Figure 3 but on a larger scale, to illustrate the notches of the stud andA the manner in which the spring fingers are seated in the notches.

As shown in the drawing:

In Figures 1 to 'l inclusive the reference numeral I0 designates generally a fastener according to this invention, detachably connecting a pair of apertured metal plates including an outer plate A such as, for example, an airplane cowling piece, and an inner plate B such as, for example, an airplane body part or cowling mounting piece.

The plate A is embossed or dimpled as at A and the embossed portion A defines a circular aperture A at the bottom thereof.

The plate B is embossed or dimpled as at B and the embossed portion B' defines a circular aperture B" at the bottom thereof. A grommet G is seated in the aperture A and has legs straddling the faces of the dimple A so as to x the grommet in the dimple.

As best shown in Figures 4 and 6, the dimple A and grommet G thereon t into the dimple B' and 6, these rivets I3 extend through holes in the plate B and have head portions seated in counterbored recesses in 'the plate B so as to :be in flush relation with the outer face of this plate.

Each foot Ila, IIa has a pair of upstanding -spring legs I Ib, IIb which curve laterally outwardly, upwardly and then laterally inwardly to an apertured plate portion IIc. The spring legs 'I Ib carry this plate portion IIe in spaced relation from the aperture B" of plate B and in alignment with this aperture. The plate portion llc has a central rectangular shaped aperture I Id therethrough.

Spring fingers I le extend from the edges of the plate portion I Ic between the legs I Ib in a curled path to provide free end portions Ile at least partially overlying the aperture IId of the plate portion Ilc.

The stud I2, as best shown in Figures 8 and 9,

y has a head portion I2a, a cylindrical shank portion I2b extending from the head I2a, and an enlarged end portion |2c on the shank portion I2b.

y This enlarged end portion I2e provides an abutment shoulder I2d and is helically grooved or threaded to provide diverging helical faces I2e extending from a point IZJ at the free end of the stud along diverging paths to grooves I2g, I2g cut perpendicularly to the axis of the stud shank.

A notch IZh is cut in each helical face I2e in advance of the groove I 2g. These notches provide flat faces or abutment shouldersv |21' parallel with the axis of the stud shank for abutting engagement with the free ends I Ie' of the spring fingers. As best shown in detail in Figure 10, the notches have the vertical walls or shoulders |21 and horizontal walls or platforms |27,

The stud head I2a is adapted to fit into the dimple A of the outer plate A and the stud shank I2b is adapted to fit freely through the grommet G carried by this dimple. The shoulder I2d on the shank, however, is of larger diameter` than the internal diameter of the grommet so that the stud is rotatably held in the plate. The stud may be equipped initially with the grommet, and the grommet can then be spun into seating engagement with the dimple A so as to mount the stud in the plate.

The point or free end I2f ofthe stud can freely enter the aperture I Id of the receptacle and the stud can then be rotated in this aperture IId until the plate portion I Ic of the receptacle is drawn down into the slots IZg. The helical faces I2e will freely ride in the aperture II d without spreading the flat sides of the aperture but, when the studhas been rotated sufficiently so that the flat sides of the aperture are seated in the slots I2g, the divergent ends of the cam surfaces will overlie the plate IIc. The stud end I2e thus has screw thread cooperation in full line contact at all times with the plate portion I Ic as `best illustrated in Figures 4 to 6. 'I'he line contact will Wear into good surface contact upon repeated locking and unlocking operations to give an actual wearing in which improves with use. Figures 4 and 5 show the threading of the stud into the plate portion IIc prior to complete rotation into fully locked position. It will be noted that the plate portionl lc is `being deflectedy to- Ward the plate B or headof the stud so that `it is inwardly bowed by the time itreaches full fastened position as shown in Figure 6.

-This inward drawing or deflection of the receptacle H causes the free ends of the lingers l le to curl downwardly and inwardly toward each other. As illustrated in Figures 4 and 6, asthe stud is beingV rotated into locke'dposition the ends- I le of the spring fingers ride along the helical faces I2e until` they reach the notched-out portions l2h. When the lingers reach these portions;v the Studis rotated into locked position with the flat side walls of the aperture lla'. on the receptacle being seated in the slots 12g and the thrusting engagement of the finger endsrlle' on the'flat spots or vertical shoulders I 2z of the stud willy resist further rotation of the stud in either direction. In addition, the rectangular hole l Id has a width which prevents rotation of the stud beyond l locked position since theV portion I2c of the stud is wider than the hole.

The spring receptacle H` can be deflected under tension load beyond locked position only until the plate portion Il c thereof thrusts against the dimple B. This dimple thus acts as a backing u member for the spring.

From the above descriptions it will be understood that the fasteners of this invention include an apertured spring plate or receptacle adapted to threadedly receive a locking stud. The spring II has fingers He with ends He', thereon which seat against the nat shoulders I 2i and on the nat platforms |27 of the notches pro-vided in the locking stud to prevent unauthorized rotation of the stud. The stud head is slotted as shown at S for engagement by a screwdriver to effect the rotation. It will be seated infull locking engagement with its receptacle upon quarter-turn rotation to fasten the parts together. Reverse quarter-turn rotation will unfasten the parts to release the stud from the receptacle.

It will, of course, be understood that various details of the inventionfmay be varied through a wide range without departing from the principles for this invention anud it is. therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the apn pended claims.

I claim as myinvention:

l. A fastener adapted for detachably connecting a plurality of apertured parts comprising a receptacle adapted to be iiXedly mounted on the innermost part and having a stud-receiving aperture adapted to overlie the aperture of said innermost part in spaced relation therefrom, a spring finger on said receptacle, a stud adapted to be rotatably mounted in the aperture of the outermost part having a helical cam portion rotatable into thel aperture of the receptacle to engage and deflect the aperture-defining receptacle portion toward the part aperture to draw the parts together, and an abutment on said stud adapted to thrust against said spring finger on the receptacle for holding the stud against unauthorized rotation.

2. A fastener comprising an apertured receptacle, spring fingers on said receptacle having deflectable free end portions, a stud vhaving 'a portion adapted to be engaged in the aperture of the receptacle, and opposed notches on said stud forming abutments for the free end portions `of said spring lingers to lock the stud against unauthorized rotation.

3. A fastener comprising a female member having an apertured central plate portion with laterally'extending spring legs, feet on the ends of said legs for attachingthe fastener to a part, a stud having a helical cam portion insertable in said aperture of the female member, said stud adapted to be rotated into locking 'engagement with the female member while deflecting fsaid spring legs, and spring fingers on said female member engageable with the stud to lock the stud againstunauthorized rotation.

fl. A fastener comprising coengaging elements, one of said elements being slotted, theother of said elementsbeing rotatable and having a head at one end and helical blades at the other'end for entry into the slotted element, said slotted ele ment yhaving spring fingers overlying the slot therein in the `path of the helical blades, and. said helical blades having shoulders thereon for locking engagement with the spring fingers to hold the rotatable element against unauthorized rotation.

5. A fastening device comprising coengaging elements, one of said elements being resilient and slotted, `the other of said elements being rotatable and having a head at one end and helical blades at its other end for entry in said slotted element into engagement therewith, spring lingers on the resilient slotted element in the path of the helical blades, and notches in said helical blades providing abutment shoulders for the spring fingers to hold the rotatable element against unauthorized rotation, said rotatable element deflecting the resilient element to position the ngers in rm engagement with the notches.

6. A fastener adapted for fastening together a plurality of apertured parts which comprises a spring plate having an aperture therethrough adapted to overlie the apertures of the parts Ato be fastened, spring legs extending laterally from said plate, feet on the ends of said legs for attaching th'e plate to a part on opposite sides of the aperture of said part, spring lingers on said spring plate extending between the spring legs and curved to present free ends in overlying relation to the aperture of the spring plate, a stud adapted to be rotatably mounted in the aperture of the outermost part having a shank extending through the apertures of the parts, an enlarged end portion on said shank having opposed helical blade surfaces diverging from a common end on the shank to diametrically opposed slots normal to the axis of the sh'ank, notches in said helical blades in advance of said slots, said helical blades adapted to be rotated th'rough the aperture of the spring plate to draw the spring plate toward the innermost part, said slots adapted to receive the spring plate therein for holding the plate in deflected position, and said spring ngers riding on said helical blades and being drawn toward each other during said delecting of the spring plate for thrusting engagement against the notched portions in the blades to hold `the studl against unauthorized rotation.

'7. A female part for a fastener comprising a spring plate having a stud-receiving aperture therethrough and feet for holding the aperturedefining portionr` of the plate in spaced relation from a part to be fastened, said plate having circularly bent spring ngers with free ends overlying the aperture and delectable into gripping engagement with a member inserted through the aperture for holding said member against rotation. l

8. -A locking stud for a fastener comprising a headed member having a shank portion with' helical blades thereon diverging from a common point on the free end of the shank to oppositely disposed slots formed perpendicularly of the axis of the shank, and notches in said blade providing abutment surfaces in advance of said slots.

9. A locking stud for a fastener comprising a member having a head portion, a cylindrical shank extending from said head, an enlarged end portion on said shank, helical grooves in said enlarged portion, opposed slots normal to the axis of the sh'ank in said enlarged portion communieating with said grooves, and notches in the grooves of said enlarged portion in advance of -said slots dening shoulders parallel with the axis of the stud.

10. A fastener adapted to detachably connect a plurality of members having embossed apertured dimples in nested relation which comprises a spring receptacle adapted to be mounted on the innermost member to straddle the dimple, an apertured plate area on said spring receptacle adapted to overlie the dimple, a stud having a head adapted to seat in the dimple of th'e outermost member, a shank on said stud adapted to exl tend through the apertures of the dimples into the aperture ofthe plate area of the spring receptacle, and locking instrumentalities on the stud shank cooperating with the plate area to deflect said area toward the dimple on the innermost member, said dimple adapted to abut said plate area to resist further deflection, and said aperture of the plate area cooperating with th'e'locking instrumentalities of the stud to resist rotation of the stud beyond locked position.

ANTHONY VENDITTY. 

